Heat exchanger

ABSTRACT

A heat exchanger including a header plate and a plurality of tubes having ends extending through the plate with an inlet tank mounted on the plate enclosing a number of the tube ends with a liquid pipe to the inlet tank for supplying liquid thereto and thereby distributing liquid by way of the inlet tank to the tubes enclosed by the inlet tank. There are also provided additional flow tank means mounted on the plate enclosing the remaining tube ends for flow of liquid through the tubes. The result of this construction is that the liquid is distributed evenly to the tubes whose ends are enclosed by the inlet tank so that flow in parallel paths is substantially uniform through these enclosed tubes.

Slaasted et al.

Jan. 1, 1974 HEAT EXCHANGER Inventors: Raymond S. Slaasted; Edward D.

Smith, both of Racine, Wis.

Assignee: Modine Manufacturing Company,

Racine, Wis.

Filed: Feb. 24, 1972 Appl. No.: 229,062

U.S. Cl. 165/144, 165/176 Int. Cl F28f 9/26 Field of Search l65/l44, I45, I76

References Cited UNITED STATES PATENTS 7/l933 Lewis et al l65/l76 Primary Examiner-Charles Sukalo Att0mey-Hofgren, Wegner, Allen, Stellman & McCord [57] ABSTRACT A heat exchanger including a header plate and a plurality of tubes having ends extending through the plate with an inlet tank mounted on the plate enclosing a number of the tube ends with a liquid pipe to the inlet tank for supplying liquid thereto and thereby distributing liquid by way of the inlet tank to the tubes enclosed by the inlet tank There are also provided additional flow tank means mounted on the plate enclosing the remaining tube ends for flow of liquid through the tubes. The result of this construction is that the liquid is distributed evenly to the tubes whose ends are enclosed by the inlet tank so that flow in parallel paths is substantially uniform through these enclosed tubes.

10 Claims, 11 Drawing Figures PATENTEU 1 374 sum 1 a? 3 UAW.

Ullk

PATENTED JAN 1 4 SHEEI 3 BF 3 HEAT EXCHANGER BACKGROUND OF THE INVENTION This invention relates to heat exchangers and is particularly applicable to a heat exchanger where liquid is directed through spaced. tubes to exchange heat with a fluid flowing over thetubes. It is especially applicable to refrigerant evaporators because the invention provides an even distribution of the liquid through the parallel tubes which is important in efficient cooling by liquid refrigerant evaporation.

SUMMARY OF THE INVENTION The heat exchanger of this invention comprises a header plate and a plurality of tubes with ends extending through the plate and an inlet tank of small extent mounted on the plate enclosing several (such as one to four) of the tube ends so that liquid supplied to this small inlet tank is subjected to turbulence and distributed evenly between the tubes for flow in parallel paths through the remaining tubes of the heat exchanger.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of the top of a heat exchanger embodying the invention.

FIG. 2 is a side elevational view of the embodiment of FIG. 1 taken from the right side of FIG. 1.

FIG. 3 is a side elevational view taken from the lower side of FIG. 1 and with portions broken away for clarity of illustration.

FIGS. 4 and 5 are plan and side elevational views of a second embodiment of theinvention.

FIGS. 6 and 7 are plan and side elevational views of a third embodiment of the invention.

FIGS. 8 and 9 are similar views of a fourth embodiment.

FIGS. 10 and 11 are similar views of a fifth embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiment of FIGS. 1-3 the heat exchanger 10 comprises spaced parallel header plates 11 and 12 through which extend the ends 13 of a plurality of parallel tubes 14. Mounted on the top plate 12 are three staggered formed inlet tanks 15 each enclosing a pair of tube ends 13. These small inlet tanks 15 are supplied with liquid refrigerant through a pipe 16 which empties into a conduit 17 that extends over the tops of the tanks 15 and communicates with each intermediate the corresponding pair of tubes 13 by way of an opening 18. Thus the inlet tanks 15 serve to distribute liquid indicated at 19 with turbulence evenly to the three pairs of tubes 14 by way of the enclosed tube ends 13 and thus to the entire heat exchanger.

The liquid flows downwardly through the tubes 14 to U-bends (not shown) on the other end of the heat exchanger and then back up through tubes 20 into a tank 21 for flow outwardly through an outlet pipe 22 as indicated by the arrow 23.

As can be seen in FIGS. 2 and 3 the header plates 11 and 12 are substantially parallel to each other with the lower plate 11 being held between the sides 24 that comprise downward parallel extensions of the ends of the top header plate 12. The lower header plate 11 is held in position between these sides 24 by inwardly extending tubes 25 and 26 struck inwardly from the parallel sides 24. This structure for mounting a header plate is the subject of Douglas E. Foster Pat. application Ser. No. 218,176, filed .Ian. 17, 1972, assigned to the same. assignee as the present application.

With the structure of the embodiment of FIGS. 1-3 the formed inlet tanks 15 serve to distribute liquid evenly to the pair of tubes 14 whose ends 13 are enclosed by each. The overlying conduit 17 serves the function of distributing the liquid evenly to the inlet tanks 15. The result is that this construction distributes the liquid evenly to all six heat exchanger tubes 14 and thereby to the other tubes 20. As mentioned, this is particularly important where the heat exchanger is an evaporator for liquid refrigerant because the efficiency of operation depends in part on the even distribution of the liquid refrigerant.

FIGS. 4 and 5 illustrate a second embodiment of the invention. In this and in succeeding embodiments the tubes are omitted except as indicated in dotted lines at the inlet because the tubes are essentially the same as the tubes 14 and 20 of the first embodiment. In this second embodiment the header plate 112 is provided with an inlet tank 115 that communicates with a pair of tubes 114 at the end of the heat exchanger 110. Mounted on top of the header plate 112 is a plurality of flow tanks 27 that are spaced from each other and that like the tanks 15 of the first embodiment enclose the ends of a pair of tubes (not shown) in the same manner that the tanks 15 of the first embodiment enclose the tank-ends 13. The result is that liquid from the inlet pipe 116 is directed into the inlet tank 115 for flow through the tubes 114 in parallel and then through successive tubes in parallel by way of the flow tanks 27. At the end of the heat exchanger opposite the inlet tank there is provided an outlet tank 28 enclosing the ends of the last two tubes 29 and 30 in each parallel set for flow of the refrigerant outwardly through the exit pipe 122.

In the embodiment of FIGS. 6 and 7 the heat exchanger 210 is provided with a similar inlet tank 215 that communicates with three parallel tubes 214 by way of an inlet fitting 31 of turbulence inducing contour (flattened cross section) having an opening 32 exhausting downwardly to about the midpoint of the elongated inlet tank 215. Flow to the fitting 31 is provided by the inlet pipe 216 and flow from the heat exchanger is through an outlet pipe 222 leading from an outlet tank 228 on the opposite end of the heat exchanger 210.

The liquid in this embodiment thereby flows in three parallel paths with succeeding tubes (not shown) in each path being interconnected by the formed flow tanks 227. Each of these tanks 227 interconnects the tube ends in the same manner as the tanks 15 interconnect the tube ends 13 of the first embodiment.

In the embodiment of FIGS. 8 and 9 the heat exchanger 310 is provided with a liquid inlet pipe 316 leading to an inlet tank 315 mounted on the header plate 312 that is similar to the header plates 12, 112 and 212 of the previous embodiments. The tank 315 communicates with a pair of tubes 314 of oval cross section similar to the tubes in the other embodiments. In this embodiment, as in the others, the liquid flows through the parallel paths by way of flow tanks 327 mounted on the plate 312 as in the other embodiments, with the final pair of tubes (not shown) exhausting through an outlet tank 328 to an outlet pipe 322.

In the embodiment of FIGS. and 11 the heat exchanger 410 has a similar header plate 412 and similar flow tanks 427 interconnecting succeeding tubes in two parallel paths in the same manner as previously described. In addition, there is an inlet tank 415 of somewhat similar shape to the one in the preceding embodiment and an outlet tank 428 with these tanks being connected with a liquid supply pipe 416 and a liquid exit pipe 422, respectively.

In each embodiment thevarious tanks are assembled on the header plates by small tubes 33 which are then bonded into an integral structure by well known bonding procedures.

The heat exchanger of this invention therefore provides for even distribution ofa liquid into parallel paths of flow and thus it is of particular importance in supplying liquid refrigerant to an evaporator. In the embodiment of FIGS. l-3 the liquid flow is through six tubes 14 in parallel and exhausts through six tubes 20. In the other embodiments the flow is in two or three parallel paths with two being used in FIGS. 4, 8 and 10 and three in FIG. 6. In all instances, however, the flow is substantially uniform because of the improved liquid distribution means of this invention.

In all embodiments the liquid inlet pipe 16-416 is arranged at an angle of less than 180 to the axes of the inlet pipes that are enclosed by the inlet tanks 15-415. Thus in FIGS. 1, 6, 8 and 10 the angle is 90. In FIG. 5 the angle is about 135".

In all embodiments the even distribution of the liquid flowing into the heat exchanger appears to be caused by the turbulence created in the flowing liquid. Thus this even distribution is achieved by the combination of the contour (and specifically the flattened cross section) of the inlet tanks 15-415 and the angle of inlet flow through the inlet pipes 16-416 relative to the inlet ends of the tubes I4-4I4. Thus in each embodiment this angle is less than l80.

Having described our invention as related to the embodiments shown in the accompanying drawings, it is our intention that the invention be not limited by any of the details of description, unless otherwise specified, but rather be construed broadly within its spirit and scope as set out in the appended claims.

We claim:

1. A heat exchanger, comprising: a header plate; fluid conveying tubes having ends extending through said plate; an inlet flow tank of flattened cross sectional contour mounted on said plate enclosing at least one but less than all of said tube ends; a liquid inlet pipe to said inlet tank adjacent to said tube ends and at an angle of less than 180 at the inlet tank to the central axis of said tube ends for supplying liquid to said inlet tank and distributing the liquid by way of said inlet tank to said tubes enclosed by said inlet tank, said contour and said angle inducing turbulence in said liquid into the inlet flow tank and thus even distribution of said liquid from said tank to said tube ends; and additional flow tanks mounted on said plate enclosing the remaining tube ends for flow of liquid through said tubes.

2. The heat exchanger of claim 1 wherein there are provided a plurality of flow tanks mounted on said plate and spaced from each other, each tank enclosing a pair of said tube ends.

3. The heat exchanger of claim 1 wherein said inlet tank encloses two of said tube ends and said liquid flows in two parallel paths through said tubes.

4. The heat exchanger of claim 1 wherein said inlet tank encloses three of said tube ends and the tubes are arranged in three sets for parallel liquid flow therethrough.

5. The heat exchanger of claim 1 wherein there are provided a plurality of said flow tanks on said plate spaced from each other each enclosing a pair of said tube ends and there is provided a conduit arranged at right angles to said tubes whose ends are enclosed by said inlet tank communicating with said inlet tank for supplying liquid to said inlet tank and thereby the tubes communicating therewith.

6. The heat exchanger of claim 5 wherein said conduit communicates with said inlet tank at an intermediate point between said tube ends enclosed by said inlet tank.

7. The heat exchanger of claim 1 wherein said angle is substantially to said axis.

8. The heat exchanger of claim 1 wherein said angle is substantially to said axis.

9. The heat exchanger of claim 1 wherein said inlet tank is provided with an inlet fitting of flattened oval cross section at the top thereof and substantially parallel thereto receiving the liquid from said pipe and having an outlet communicating with said tank.

10. The heat exchanger of claim 9 wherein said outlet is positioned substantially centrally between the ends of said inlet tank.

Disclaimer and Dedication 3,7 82,454.Raym0nd S. SZaasted and Edward D. Smith, Racine, Wis. HEAT EXCHANGER. Patent dated Jan. 1, 1974. Disclaimer and dedication filed Apr. 26, 1974:, by the assignee, Modine Manufactum'ng 00mgumy.

Hereby disclaims and dedicates t0 the Public the entire remaining term of said patent.

[Oyfioz'al Gazette August 2'7, 1974.] 

1. A heat exchanger, comprising: a header plate; fluid conveying tubes having ends extending through said plate; an inlet flow tank of flattened cross sectional contour mounted on said plate enclosing at least one but less than all of said tube ends; a liquid inlet pipe to said inlet tank adjacent to said tube ends and at an angle of less than 180* at the inlet tank to the central axis of said tube ends for supplying liquid to said inlet tank and distributing the liquid by way of said inlet tank to said tubes enclosed by said inlet tank, said contour and said angle inducing turbulence in said liquid into the inlet flow tank and thus even distribution of said liquid from said tank to said tube ends; and additional flow tanks mounted on said plate enclosing the remaining tube ends for flow of liquid through said tubes.
 2. The heat exchanger of claim 1 wherein there are provided a plurality of flow tanks mounted on said plate and spaced from each other, each tank enclosing a pair of said tube ends.
 3. The heat exchanger of claim 1 wherein said inlet tank encloses two of said tube ends and said liquid flows in two parallel paths through said tubes.
 4. The heat exchanger of claim 1 wherein said inlet tank encloses three of said tube ends and the tubes are arranged in three sets for parallel liquid flow therethrough.
 5. The heat exchanger of claim 1 wherein there are provided a plurality of said flow tanks on said plate spaced from each other each enclosing a pair of said tube ends and there is provided a conduit arranged at right angles to said tubes whose ends are enclosed by said inlet tank communicating with said inlet tank for supplying liquid to said inlet tank and thereby the tubes communicating therewith.
 6. The heat exchanger of claim 5 wherein said conduit communicates with said inlet tank at an intermediate point between said tube ends enclosed by said inlet tank.
 7. The heat exchanger of claim 1 wherein said angle is substantially 90* to said axis.
 8. The heat exchanger of claim 1 Wherein said angle is substantially 135* to said axis.
 9. The heat exchanger of claim 1 wherein said inlet tank is provided with an inlet fitting of flattened oval cross section at the top thereof and substantially parallel thereto receiving the liquid from said pipe and having an outlet communicating with said tank.
 10. The heat exchanger of claim 9 wherein said outlet is positioned substantially centrally between the ends of said inlet tank. 